The field of the invention relates generally to passenger comfort within aircraft cabins, and more specifically, to an alternate directional momentum ventilation nozzle for passenger cabins.
A problem exists when attempting to provide conditioned air in the passenger cabins of aircraft to meet the thermal comfort needs of the passenger cabin occupants. The seated passengers' thermal comfort is dependent on the air supply nozzle to satisfy the following conditions at the passenger head level: a lower air velocity (no air draft), a reduced temperature stratification across the passenger cabin, and an adequate ventilation effectiveness. However, in the aisles, it is necessary to have a relatively higher air flow at the standing occupant head level to satisfy the flight attendants' thermal comfort.
Satisfying the thermal comfort for all occupants within an aircraft cabin is a challenge due to the required high air flow volume into the enclosed and limited volume of the passenger cabin. Additionally, the interior design requirement is to keep the air distribution nozzle outlets as small as possible. This requirement necessitates higher air flow velocity at the nozzle outlet to deliver the required conditioned volumetric air flow. Diffusing the nozzle air jet speed before the air reaches the cabin occupants is another challenge.
Currently most passenger airplanes use air supply nozzles in the passenger cabins with two-dimensional air flow at the nozzle's outlet. Additionally, most of these nozzles have large outlet areas. These two dimensional air flow nozzles have the same air flow distribution pattern at any section along the passengers' cabin. Nozzles with two-dimensional air flow have an outlet air flow in one direction which cannot be diffused rapidly before reaching the passengers and results in a high air draft with low air temperature at the center seats of the cabin, high temperature stratification across the cabin, and a lower air velocity in the aisles, all of which contribute in a reduced passenger thermal comfort.
Adding to the challenges described above, additional features added to current passenger aircraft contribute to increasing electrical heat dissipation within the passengers' cabin. To counteract this increase in heat, additional cooling is required which can only be achieved by providing a cooler air supply and/or a higher volumetric flow. The existing nozzle designs with two-dimensional outlet air flow can not satisfy the passengers' thermal comfort with the additional demands for a cooler air supply and/or a higher volumetric air flow.